1. Field of the Invention
This invention is directed to a time division multiplexing load control system and, more particularly, to a time division multiplexing load control system comprising a central controller unit which controls terminal units to connect and disconnect loads connected thereto and manual switch means located on the side of each terminal unit which controls the loads independently of, but without disturbing, the central controller unit.
2. Description of the Prior Art
In a conventional time division multiplexing transmission control system wherein a central controller unit accesses sequentially a plurality of terminal units connected thereto, it takes an increasing amount of time to complete a control as the number of terminal units increases. For example, assuming an access time per channel of 15 msec, the entire access time for a system containing 256 channels will be as much as 3.84 sec (256.times.15.times.10.sup.-3 sec), so that when the terminal units are utilized, such as for lighting control, an operator may sometimes wait a few seconds after the moment of his operation until the desired lighting fixture goes on or off. Therefore, the operator may be uncertain of his manipulation during such a time-lag, and particularly an operator in a dark room will have a false anxiety until the light turns on. This undesirable time-lag, from the instant of manipulating a switch to the moment when the load actually responds to turn on and off, will increase with an increasing number of loads to be controlled.